1. Field of Invention
The present disclosure relates to an optical reflection plate and a lighting device having the same.
2. Description of Related Art
In daily life, lighting devices are indispensable tools. Conventional lighting devices include light bulbs or lamps which are used as the light sources therein. Fluorescent tubes, incandescent bulbs, or halogen light bulbs are typically used for such light bulbs or lamps. Since these light sources consume a lot of electrical energy when emitting light, lighting devices including light-emitting diodes (LED) as light sources have become more and more popular in recent years. In addition to low power consumption, an LED lighting device has a long life span, small size, is not easily affected by shaking movement (such as that encountered during an earthquake), can be used in many different applications, and also is not easily broken.
Regardless of the type of light source that is used in a lighting device, the light uniformity of the light emitted therefrom is very important for the eye comfort of users. For example, when the light uniformity of the light emitted from a lighting device is bad, an illuminated region (e.g., a desk) may have bright and dark regions. Viewing such an illuminated region easily leads to eye discomfort for users.
FIG. 1 is a perspective view of a conventional lighting device 100. The conventional lighting device 100 includes a housing 140, a light holder 120, a light source 122, a reflection plate 110, and a light transmissive plate 130. The light holder 120, the light source 122, and the reflection plate 110 are accommodated in the housing 140, and the light transmissive plate 130 is located on the housing 140 and corresponds to the position of the reflection plate 110 (i.e., is spaced apart from the reflection plate 110 at a location opposite to the same). The light source 122 is located on the light holder 120. When the light source 122 emits light, the light emitted from the light source 122 is reflected by the reflection plate 110. Thereafter, the light passes through the light transmissive plate 130. The reflection plate 110 causes the light emitted from the lighting device 100 to become uniform.
Nevertheless, although the light uniformity of the lighting device 100 can be improved by adjusting the angle and the position of the reflection plate 110, if the housing 140 and the reflection plate 110 of the lighting device 100 have been completely manufactured by molding, a uniform light-emitting surface is not easily adjusted due to the limited space of the lighting device 100. For example, the position of the reflection plate 110 fixed on the housing 140, and the shape and size of the reflection plate 110 are difficult to change.